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Question
Cards numbered 1 to 30 are put in a bag. A card is drawn at random from the bag. Find the probability that the number on the drawn card is a prime number greater than 7.
Solution
Let E2 be the event of getting a prime number greater than 7.
Out of these numbers, prime numbers greater than 7 are 11, 13, 17, 19, 23 and 29.
Number of favourable outcomes = 6
∴ P(getting a prime number greater than 7) = P(E2) = `("Number of outcomes favourable to" E_2)/"Number of all possible outcomes"`
`= 6/30 = 1/5`
Thus, the probability that the number on the card is a prime number greater than 7 is `1/5`.
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